We have been getting some OutOfMemoryErrors and the heap dumps are showing lots of memory being held by org.hibernate.impl.SessionImpl. The last dump showed 6 of these each holding about 200MB (about 1.2GB total). We have been working with a outsource partner, so my information is very limited, but I can tell you the level packaged in the war is 3.2.1. I saw there was a memory leak fix in 3.2.3 and it looks like the current final version is 3.6.5. My question is this, is it OK to upgrade that many levels in one fell swoop? Would I expect to see any backward compatibility issues or any unwanted change in behavior? Even better, are there "gotta have" fixes or improvements that we would want anyway? We will likely conduct an internal test, but I wanted to get some feedback from the experts here before I recommend that. Thanks in advance.

Frank